Designation for Specific Inductive Capacity. See Dielectric Constant.

A difference in gauge between the two edges of a sheet.

The pressure on a cable that is being pulled around a curved surface under tension. If excessive, this pressure can damage cable components and reduce the life of the cable.

The normal force exerted on a cable under tension at a bend.

The pressure exerted on a cable in the inside of a conduit or tubing at a bend.

The derived S.I. unit for conductance: one siemens equals one ampere per volt.

A woven wire assembly used as a separator of particles of different sizes. See Riddle.

The rating of the size of openings in a sieve, which is reported as the number of openings per measured area. For example, 320 mesh means there are 320 openings per linear inch.

A cable designed to carry current of usually less than one ampere per conductor to operate signal circuit devices.

An individual conductor used to transmit an impressed signal.

An alloy that contains silicon and manganese. It is used as a deoxidizer in the furnace and for the introduction of manganese and silicon into steel.

Element, chemical symbol Si. Silicon, one of the most abundant elements on earth and a powerful de-oxidizing agent, is a major portion of silica and silicates (rocks, quartz, sand and clay). Its inclusion improves the physical properties of steel. Combined with manganese, it is used in materials for springs of various types and gives best service in this capacity when combined with a carbon content of from 0.45 to 0.70 percent. A silicon content generally limited to 4 percent is used for electric resistance wires as it increases electrical resistance. Also used as an alloying element with copper and aluminum.

Consists of about 3 percent silicon, 1 percent manganese and the balance is copper. It is strong and tough with excellent corrosion resistance. The tensile strength of this alloy is greater than that of brass and comparable to that of many ferrous materials.

A hard abrasive pro­duced artificially, which is used for drilling and finishing of sintered carbide dies. Used only in loose form. It is heat resistant and chemically resistant. Widely used for grinding and other abrasive purposes, and as a refrac­tory.

The complete saturation of insulating tapes or braids, with a silicone varnish compound. The process may be performed under a vacuum. The compound serves as a heat and flame retardant as well as a binder.

A nickel-base alloy wire containing from about 0.5 to 3 percent manganese and from 1 to 4 percent nickel. It has a very high resistance to corrosion and high-temperature effects.

Steel alloys with an approximate composition of 2 percent silicon and 1 percent manganese are often used for springs subjected to severe fatigue conditions, while 1.8 to 2.5-percent silicon, 0.70 to 0.90-percent manganese and 0.50 to 0.70-percent carbon composi­tion is used for instrument springs.

A non-metallic material typically made from four elements: silicon, oxygen, hydrogen and carbon. It can be in a thermosetting elastomer or liquid form. The thermosetting elastomer form is noted for high heat resistance. They are polymeric materials in which the recurring chemical group contains silicon and oxygen atoms as links in the main chain. Various organic groups are attached to the silicon atoms and enhance performance of the silicone polymer. Methyl groups are most common and provide good heat and UV resistance, phenyl groups provide low temperature resistance, while fluorine containing groups provide fuel and non-polar solvent resistance. Silicone rubber extrusions offer retention of good electrical properties, resilience and flexibility after long-time heat aging.

An elastomer made from silicone polymer and silica. Possesses great chemical stability, and an extraordinary degree of heat resistance for a rubber-like material in that it can be used for cable insulations at temperatures up to about 150°C for long periods without any apparent changes. It usually needs some form of external protection to prevent abrasion during installation. Cables of this type are used in specialized applications such as wiring of flues and brick kilns where high temperatures are en­countered.

A silicone liquid treatment applied to insulated conductors to allow for easy jacket stripping.